Dogwoods-Landscape Trees with Four Season Appeal
“The aristocrat of native flowering trees”
Cornus florida, our native flowering dogwood, and its cultivars are among the most beloved flowering trees. Although slow-growing, dogwoods can reach heights of twenty to twenty-five feet and similar spreads. They usually flower in April to May, and white, pink, and red flowers are available. The "flowers" are actually bracts, or modified leaves, while the actual flowers are the spiky-looking clusters in the center. Often overlooked are the bright red berries that appear in small clusters in September to October. Fall leaf color is red to reddish purple for most varieties. Add to that an interesting winter habit and you have a tree with four-season character.
There are three cardinal rules of dogwood care:
Avoid afternoon sun Provide good drainage Don't overwater
Cornus florida
Dogwoods prefer filtered light or morning sun/afternoon shade. You will see them living in hot, sunny locations, but they are very, very difficult to establish in afternoon sun. Dogwoods can't stand to have their roots saturated for very long. For this reason, we add lots of soil conditioner, plant them higher than surrounding ground, use high phosphorous fertilizer, and water frequently but lightly. The two most common dogwood ailments are powdery mildew and leaf spot anthracnose. Both can be readily controlled with the fungicide Chlorothalonil. A similar-looking but deadly anthracnose disease can also affect dogwoods, and can be controlled with Chlorothalonil , mancozeb + thiophanate methyl or propiconazole. Commonly available varieties of Cornus florida include:
’Cherokee Brave’ - bright red flowers
’Cherokee Daybreak’ - beautiful variegated form, will not scorch in summer heat; upright habit
’Cherokee Princess’ - large white flowers, consistently heavy bloomer
’Cherokee Sunset’ - yellowish and green leaves, beautiful fall color that changes from pink to red to purple
’Cloud 9’ - profuse white flowers, best bloomer as a young tree
Pink - our regular pink dogwood
White - the species variety
Cornus kousa
Cornus Kousa - Kousa or Chinese dogwood, reaches approximately the same size as Cornus florida but develops a distinctly horizontal branching pattern. Its white flowers also are more star-shaped, with four pointed bracts. Other major differences are that Kousa will tolerate full sun, flowers about three weeks later, and is resistant to most of the insect and disease problems associated with our native dogwoods. Kousa are also more drought tolerant but still require excellent drainage. Fall color may be inconsistent but its large red fruit is quite showy. (The fruit can get a little messy, so consider that when planting.) Available varieties include:
’Milky Way’ - abundant white flowers
’Satori’ - a recently developed pink flowering variety
Kousa - creamy White 4-"petaled" flowers borne above foliage along branches, the species variety
’Wolfeye’ - Outstanding variegated dogwood, slow growing with great reddish fall color
The Rutgers‘ Hybrids - Developed at Rutgers University to combat the killer anthracnose that does exist in the northeast, this group of hybrids are a cross between Cornus florida and Cornus kousa. Our experience indicates that they are definitely resistant to leaf spot and powdery mildew and tolerate hot sun more than Cornus florida. They also flower later than C. florida, after the leaves appear. Available from this group are:
’Celestial’ - white flowers
’Aurora’ - white flowers, somewhat upright
’Constellation’ - white flowers
’Stellar Pink’ - pink flowers, somewhat upright habit
Other dogwoods of landscape value exist, such as the red and yellow-twig varieties, but are not discussed here because they are essentially shrubs.